Piston-packing



PATENTED FEB. 16, 1904 0. B. DAWSON. PISTON PACKING.

APPLIOATION FILED JULY 31, 1902.

K0 MODEL.

[NVEAL-TOR nv ssas. Z I. ATTORNEY Patented February 16, 1904.

PATENT OFFICE.

CHARLES E. DAWSON, OF CLEVELAND, OHIO. I

PlSTON -PACKING.

SPECIFICATION forming part of Letters Patent No. 752,046, dated February 16, 1904. Application filed. July 31, 1902. Serial No. 117,816. (No model.)

To all whom, it may concern:

Be it known that I, GHARLEs E. DAWSON, a citizen of Great Britain, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Piston-Packing, of which the following is a specification, reference being had therein to the accompanying drawings.

The annexed drawings and the following description set forth in detail one mechanical form embodying the invention, such detail construction being but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure 1 repre' sents a side view of two connected pistons provided with my improved packing, one of said pistons being shown partly in section; and Fig. 2, a transverse section on the line 2 2 in Fig. 1 of one of said pistons.

The two pistons a are illustrated as connected by a body A, and each piston has an annular groove a, into which the packing is placed. A coiled fiat spring E is placed into this groove, and a wrapping C of a strand of textile, such as a cord or band, is tightly wrapped around this spring to compress the same and hold it compressed. Metallic packing-rings B, formed from sections 0, are

placed outside of and against the textile wrapping. This fibrous strand wrapping may be made from asbestos cord if subjected to considerable heat. The spring is coiled and the wrapping wound so as to permit the packingrings to properly fit in the cylinder without compression of the spring and wrapping and without the need for expansion from within, which is rendered impractical by the wrapping. The end of the cord or strip forming the wrapping is free, so as to permit a very slight and slow expansion of the spring and wrapping by the windings of the latter slowly slipping upon each other as the rings wear and the wrapping becomes compressed, so that such wear and compression may be slowly taken up as it occurs and the packing-rings may always have a good fit in the cylinder. This piston-packing does not act by spring expansion from within, forcibly bringing the rings to bear against the interior of the cyliny invention may inder,but allows the packing-rings to originally have a goodfit in the cylinder and to maintain the same by the gradual and gentle expansion of the coiled spring as the windings of the wrapping slip upon each other and just take up whatever loosenessof the fit the packing-rings may acquire during use. Whatever expansion does take place is perfectly even all around the piston and cannot again be compressed, owing to the resistance of the expanded spring, so that the packing-rings will have a completely even bearing on their entire circumference. It is by this even and gentle but very slow expansion and the impossibility of it being again compressed that this packing differentiates from the class of piston packings in which the packing-rings are sprung outward andheld with force against the cylinder.

Other modes of applying the principle of be employed for the mode herein explained. Change may therefore be made as regards the mechanism thus disclosed, provided the principles of construction set forth, respectively,- in the following claims are employed.

I therefore particularly point out and distinctly claim as my invention 1. The combination with a piston having a circumferential groove, and an expansible packing-ring, of a coiled spring in the groove anda wrapping around said spring confining the same and withinthe packing-ring.

2. The combinationwith a piston having a circumferential groove, and an expansible packing-ring, of a coiled spring in the groove and a fibrous strand wrapped around said coiled flat spring confining thesameand within the packing-ring. s

3. The combination with a piston having a circumferential groove, and an expansible packing ring, of a coiled flat spring in the groove and a wrapping around said spring confining the same and within the packing-ring.

4. The combination with a piston having a circumferential groove, and an expansible packing ring, of a coiled flat spring in the groove and a fibrous strand wrapped around said coiled fiat spring to form a wrapping confining the same and Within the packing-ring.

5. The combination with a piston having a circumferential groove, and a sectional packing-ring, of a coiled flat spring in the groove, and a wrapping around said spring consisting of a fibrous strand wrapped around the spring to confine the same and to fit Within the sectional packing-ring.

6. The combination of a piston having a circumferential groove, a coiled flat spring in the I 0 bottom of said groove, a wrapping consistin g of In testimony whereof I afiix my signature in I 5 presence of two witnesses.

CHARLES E. DAWSON. Witnesses:

F. D. AMMEN, F. D. DALEY. 

